Tony Anziano, Caltrans' toll bridge program manager, sits in a section with unbroken rods under the new Bay Bridge span.

Photo: Lea Suzuki, The Chronicle

Tony Anziano, Caltrans' toll bridge program manager, sits in a...

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A shear key containing both broken anchor rods and still-tensioned rods are seen on the new Bay Bridge on Friday, May 3, 2013.

Photo: Lea Suzuki, The Chronicle

A shear key containing both broken anchor rods and still-tensioned...

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Anchor rods are seen in a shear key at the new Bay Bridge on Friday, May 3, 2013. These anchor rods were not broken.

Photo: Lea Suzuki, The Chronicle

Anchor rods are seen in a shear key at the new Bay Bridge on...

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A broken anchor rod rises up next to still-tensioned rods on a shear key on the new Bay Bridge on Friday, May 3, 2013.

Photo: Lea Suzuki, The Chronicle

A broken anchor rod rises up next to still-tensioned rods on a...

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A section of bolt removed from the new Bay Bridge in undergoes a Rockwell hardness test at Caltrans TransLab in Sacramento, California, May 9, 2013. Caltrans is testing the so-called "2010 rods", following the failure of 32 three-inch steel rods that broke during construction.

Photo: Max Whittaker/Prime, Special To The Chronicle

A section of bolt removed from the new Bay Bridge in undergoes a...

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Caltrans deputy director Will Shuck holds a section of bolt to be tested after the failure of some rods during construction in 2013.

Photo: Max Whittaker/Prime / Special To The Chronicle

Caltrans deputy director Will Shuck holds a section of bolt to be...

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Caltrans deputy director Will Shuck holds a section of bolt removed from the new Bay Bridge in preparation for testing at Caltrans TransLab in Sacramento, California, May 9, 2013. Caltrans is testing the so-called "2010 rods", following the failure of 32 three-inch steel rods that broke during construction.

A section of bolt removed from the new Bay Bridge for testing at Caltrans TransLab in Sacramento, California, May 9, 2013. Caltrans is testing the so-called "2010 rods", following the failure of 32 three-inch steel rods that broke during construction.

The federal government will investigate how Caltrans allowed more than 2,300 suspect steel rods to be installed on the new Bay Bridge eastern span and will review the agency's $10 million fix of more than two dozen that have already failed, officials said Monday.

The probe will be conducted by the Federal Highway Administration, which agreed to come in at the request of a state-local panel overseeing the $6.4 billion eastern span. The panel, which represents both Caltrans and the Metropolitan Transportation Commission, sought an "arm's length" review of the problems with high-strength, galvanized threaded rods installed on the bridge since 2007.

Problems with the rods have raised questions about whether the span will open to traffic as scheduled on Sept. 3. A spokesman for the federal agency would not speculate on how long its examination might take.

"Our work has just started," said Doug Hecox, spokesman for the highway administration.

The federal agency's immediate concern is whether Caltrans' proposed solution to the failure of 32 threaded steel rods will work. Those rods are vital to structures designed to keep the span from swinging wildly in an earthquake, but they snapped shortly after workers tightened them in March.

$10 million solution

Rather than replace the now-inaccessible rods, Caltrans wants to construct a saddle that would be strapped onto the seismic structures using high-strength steel strands. The saddle fix would cost $10 million, the state says.

On a larger scale, the Federal Highway Administration wants to know how the 32 rods and more than 2,300 others came to be installed on the span in the first place.

A number of outside experts have said Caltrans took an unacceptable risk by ordering excessively hard rods that were vulnerable to hydrogen invasion, either when they were galvanized or when they were exposed to the elements, that could cause them to become brittle and crack.

Tower rods

On Sunday, The Chronicle reported that the problematic rods included more than 400 installed at the base of the span's signature tower. Caltrans says visual checks haven't found any cracks, but concedes that the rods are all but inaccessible and are difficult to test.

Caltrans officials are scheduled to testify Tuesday before the state Senate transportation committee, whose chairman says the agency's quality controls appear to have been lacking.

"The question is, who knew what? And when?" said state Sen. Mark DeSaulnier, D-Concord, who will oversee the hearing.

The tower rods were made of high-strength steel and galvanized in molten zinc, a combination that Caltrans has banned for bridge construction and has been subject to warnings by federal highway officials for decades. The agency made an exception to the ban for the new bridge, citing the single-tower suspension span as an unusual design calling for unusual measures.

Caltrans specified steps during manufacturing to reduce the risk that the 24-foot rods could become brittle from hydrogen and crack, but the supplier says the state's instructions never reached it.

Caltrans says the rods are not at high tension, reducing the risk they could crack.

DeSaulnier said he was disturbed by the apparent breakdown at Caltrans, which was supposed to make sure the rods were safe.

"The overall lack of quality control is really quite deplorable," he said.

Third-party probe?

A briefing paper prepared by the Senate Transportation and Housing Committee's staff in advance of Tuesday's hearing concludes that it "is becoming increasingly difficult for the Legislature and the public to simply believe in Caltrans' reassurances when problems continue to arise and the experts who designed and constructed the bridge give the 'all clear.'

"It seems a truly independent third-party validation of the new span's design and construction may be necessary to determine its level of safety," the report said. It suggests that a panel of University of California professors or an independent, nonprofit think tank could take on the job.

"Californians who ultimately paid for the bridge deserve a frank, honest, and informative discussion of the new span to determine what they purchased," the report said.

'Pushing for the solution'

Amy Worth, head of the Metropolitan Transportation Commission - a panel made up mostly of elected Bay Area officials - said she will be monitoring Tuesday's hearing for answers. She also welcomed the Federal Highway Administration's involvement.

"I keep pushing for the solution and the story about what the process was - that's what we have to get," she said. "We've got to get this right."